30m Long Distance Gear-Driven Mousetrap Car

This high-efficiency mousetrap car is powered purely by the spring mechanical energy of a Windhager mousetrap and utilizes a real gear system to maximize distance. The design runs incredibly smooth and achieved a personal track record of exactly 30 meters! To wind it up, the car must be rotated by three-quarters of a turn at the main gear, featuring a gear ratio of 1 to 64.

Required Hardware:

• 6x 6700 ZZ Ball Bearings (10 x 15 x 4 )
• 1x M3 Socket Head Screw 43 mm total length, partially threaded with a 20 mm smooth shank
• 1x Windhager Mousetrap

Step-by-Step Guide:

1. Spring Preparation: Remove the spring from the Windhager mousetrap. Trim the protruding wire ends so that about 2 cm remain, and bend them so they stick out at a 90° angle relative to the spring.
2. Inserting the Spring & Sleeve: Push the printed plastic sleeve inside the spring. Then, insert the spring into the main motor cavity of the chassis with the thicker side of the spring facing inward.
3. Main Gear & Core Screw: Place the large main drive gear onto the spring. Pass the M3 screw through the gear and the spring to lock everything into place. Tighten it enough to eliminate wobbling, but ensure it remains loose enough to spin freely without excessive friction.
4. Gearbox Assembly: Press one ball bearing into each of the middle gears. If the fit is tight, gently tap them in using a hammer. Carefully mount these geared assemblies onto their designated pins on the chassis.
5. Axles & Wheel Bearings: Install the axles along with the remaining bearings onto the frame. Tip: For the wheel axles, you can optionally use 3D-printed bearings. However, for the high-load drivetrain gears (Step 4), real metal ball bearings are strictly required!
6. Attaching the Wheels: Finally, press-fit the wheels onto the axles – the large wheels go in the back, and the small wheels go in the front.